date: Fri, 15 Jun 2001 13:29:32 -0400
from: "Michael E. Mann" <mannatXYZxyzginia.edu>
subject: Re: workshop report
to: Julia Cole <jcoleatXYZxyz.arizona.edu>
Thanks for your comments. They are helpful, and well taken. I'm not sure we can accommodate
significant discussion of *all* of the issues you mention, because of limited space and a
need to discuss a wide range of things. But we can certainly tweak the emphasis and
reorganize the discussion as you recommend.
Lets wait for the comments from the others. At that point, may I request (if you are
willing) that you and Malcolm work on a revised draft that incorporates your comments,
Malcolm's additions, and the concerns/suggestions expressed by the others, as you hinted
you might be willing to do? I'll probably want to take one more crack at finalizing it
after you are done, then we can send it out one last time to the group for final comments.
Please let me know if you are amenable to this. Thanks,
At 09:22 AM 6/15/01 -0700, Julia Cole wrote:
Just finished the draft report and overall, it looks like a great start. I want to make
a few comments though, which I hope are not too odious to implement. Please let me know
if you want actual rewriting from me.... I'm guessing you'll need to do it yourself to
incorporate everyone's input, however.
In general, I think shorter paragraphs would be better and I have tried to break these
up in my comments. Remember that EOS columns are narrow, and a paragraph that is a half
page here will be really long in EOS!
In para 1, second line, I think you mean "natural variability of the modern and
near-future climate"; obviously the natural variability of climate over all time scales
exceeds that of the late Holocene. Where you cite Crowley, you might also want to cite a
GCM-based analysis (Rind et al 1999 JGR, or Robertson et al. if Peck says its citable -
these refs are below).
More philosophically - the initial two paragraphs are focused on one way of looking at
climate - the large-scale (hemispheric/global) reconstruction of temperature and
explaining that variability. We spent a couple days of workshop on regional
reconstruction targeting ENSO, NAO, hydrologic variability on different continents,
etc., but that doesn't appear until several paragraphs later. Your "three distinct
approaches" really needs to come under a later header of large-scale temperature
reconstruction, and before this is introduced, the issue of regional reconstructions
needs to be mentioned. You can break up the first two paras into shorter units if you do
this. Can you create headers to break up the article?
Begnning of third para - I think you might specify that you are referring again to
discrepancies in large-scale T reconstructions...
In third and fifth paragraphs, you seem to imply that borehole records are not
"proxy-based" records. But borehole data are proxies for surface air temperature, are
they not? I think this subtle distinction will be lost on many, which will obscure your
meaning. Maybe better to distinguish "multiproxy", "tree-ring", and "borehole"
reconstructions for more clarity.
Final para: first, I think you can make this three paras with minimal rewriting - one on
data gaps, one on need for low-res records, and one on validation. Third line - when you
say database, it sound like we need better organization of the data we have - but what
we really need I think is more and better data. We should state this more clearly in
that sentence - you go on to say what's needed, so I think this is what you mean too.
Third sentence - eliminate "(particularly the extratropics)" - it contradicts your first
clause in that sentence; you can also eliminate "related" since what we need are proxies
of ENSO variability. 4th sentence - "climatically key" for what? Lets just say "data
sparse". Instead of "currently emphasized high resolution", how about just "annual".
Later on, there's that borehole vs proxy distinction again that can be clarified.
We did also identify the nineteenth century as an interesting interval for
reconstruction - one that is uncontaminated by anthropogenic forcing, for the most part.
That is nowhere in here. There are interesting changes in ENSO (Urban et al) and the NAO
(Heinz and Jurg told me about this - perhaps it is in the NAO review paper) whose
impacts would be really interesting to decipher.
That's it for specific changes - I can see a few places where the number of words can be
reduced w/o changing meaning, and if you want me to go through that later, I'd be happy
to - but without getting everyone else's input first, it might be a waste of time to try
Rind, D., J. Lean, and R. Healy, Simulated time-dependent climate response to solar
radiative forcing since 1600, Journal of Geophysical Research-Atmospheres, 104 (D2),
Robertson, A.D., J.T. Overpeck, D. Rind, and R. Healy, Simulated and observed climate
variability of the last 500 years, Science, to be submitted June 2001, 2001.
Dr. Julia Cole
Dept. of Geosciences
1040 E. 4th St.
University of Arizona
Tucson AZ 85721
Professor Michael E. Mann
Department of Environmental Sciences, Clark Hall
University of Virginia
Charlottesville, VA 22903
e-mail: mannatXYZxyzginia.edu Phone: (804) 924-7770 FAX: (804) 982-2137